Service Bulletin No. 3102
MODEL

TYPE

J4500

SECTION/GROUP

Service Information

DATE

8-Engine

Mar. 22, 2017

SUBJECT

AMEREX FIRE SUPPRESSION SYSTEM NOZZLE POSITION
CONDITIONS

Service Information Only.

Description:
Motor Coach Industries ("MCI") has become aware that some J4500 model coaches equipped with a DD13 engine
may experience difficulty removing the oil filter due to the position of the Amerex fire suppression system nozzle.
This service information bulletin is applicable to J4500 coaches equipped with an DD13 engine and the Amerex fire
suppression system between the unit range of, and including, unit numbers 67621 to 67937.

Service Procedure:

Read this entire procedure before beginning work.
Use Safe Shop Practices At All Times.

To avoid personal injury, never enter or perform work in the engine compartment prior to positioning the
ENGINE RUN and ENGINE START switches on the engine compartment remote control box to the OFF
position. Allow enough time for components to cool down prior to working in the engine compartment.

Service Bulletin No. 3102
Date Mar. 22, 2017

Page 2

1. Turn the main battery disconnect to the OFF position.
2. Chock both sides of the tires.

Ensure that the engine compartment door is secured in the open position prior to working in the
engine compartment.

3. Open the engine compartment door.
4. Locate the Amerex hose / nozzle assembly and mounting bracket in the upper curbside section in the
engine compartment shown in Figure 1.

Figure 1. Amerex nozzle location in the engine compartment.

Service Bulletin No. 3102
Date Mar. 22, 2017

Page 3

5. Locate the Amerex hose / nozzle assembly installations ( pre and post retrofit ) shown in Figure 2.

3

1

2

Figure 2. Retrofit installation mounting information.

Item

Figure 2 Description

1

existing installation with assembly mounted on the inboard side of the frame bracket

2

retrofitted installation with assembly mounted on the outboard side of the frame bracket

3

frame bracket

Service Bulletin No. 3102
Date Mar. 22, 2017

Page 4

Figure 3 is a reference photo for retrofit part identification.
The pre-retrofit bracket assembly will be mounted on the opposite ( in-board ) side of the frame
bracket. Figure 3 shows the post-retrofit installation.
6. Remove and retain the mounting hardware from the bracket shown in Figure 3.
7. Using two wrenches, disconnect the nozzle assembly from the fitting on the Amerex hose assembly shown
as Items 2 and 3 in Figure 3.

1
4

1
3
2

5

Figure 3. Reference photo for part identification and retrofit steps.

Item

Figure 3 Description

1

mounting bracket hardware

2

Amerex hose with assembly fitting on end

3

position a wrench on the Amerex hose assembly fitting

4

position a wrench on the nozzle assembly elbow

5

street elbow nozzle assembly

Service Bulletin No. 3102
Date Mar. 22, 2017

Page 5

8. Place the bracket assembly ( bracket, nozzle assembly elbow and street elbow ) on a work bench.

The fittings will be orientated 180° opposite from the original routing to facilitate the bracket
re-orientation ( refer to Figure 4 ).

2

1

Figure 4. Bracket assembly fitting orientation.

Item

Figure 4 Description

1

existing orientation

2

retrofitted orientation

9. Using two wrenches, remove the nozzle assembly elbow and street elbow from the bracket. Clean to
remove any sealant residue from all fittings and bracket port threads.
10. Apply a thin layer of airline pipe sealant to the external fitting threads, leaving three ( 3 ) threads bare.
11. Orient and install the nozzle assembly elbow and street elbow, hand tight, to the bracket as orientated
shown as Item 2 in Figure 4.

Service Bulletin No. 3102
Date Mar. 22, 2017

Page 6

12. Using the existing hardware, install the bracket assembly to the engine compartment bracket orientated as
shown in Figures 3 and 5. Tighten capscrews to secure.
13. Using two wrenches, turn to tighten the nozzle assembly elbow to orient with the Amerex hose assembly
fitting, ensuring a minimum of three ( 3 ) external threads bare.
14. Using two wrenches, reconnect the nozzle assembly elbow to the Amerex hose assembly fitting. Tighten to
secure installation.
15. Using two wrenches, turn to tighten the street elbow nozzle to orient the discharge nozzle to the A/C
compressor area of the engine compartment. Ensure a minimum of three ( 3 ) external threads bare ( refer
to Figure 3 ).

Figure 5. Photo of completed retrofit.
16. Close the engine compartment door.
Procedure Complete.